The present invention relates to a method and device for controlling a plurality of combustors supplying a pressurized gas to a gas turbine.
In a conventional device for controlling a plurality of combustors supplying a pressurized gas to a gas turbine as shown in FIGS. 3, 4A and 4B, air A from a compressor (not shown) is supplied into a combustor 115 through a casing 110, diffusion combustion air supply orifices 113 of a diffusion combustion chamber 130, air supply orifices 114 of a pre-mix combustion chamber 131 and pre-mix combustion air supply orifices 133 of a pre-mixing swirler 132. A diffusion combustion fuel F1 is injected from diffusion combustion nozzles 134 into the diffusion combustion chamber 130, a pre-mix combustion fuel F2 is injected from pre-mix combustion nozzles 135 into the pre-mixing swirler 132. Air heated by a fuel combustion, to be pressurized is supplied from the combustor 115 to a gas turbine 138 to rotate the gas turbine 138. An open area of the pre-mix combustion air supply orifices 133 is changed by a valve 118 driven by a driver 121. A controller 119 controls a supply rate of the diffusion combustion fuel F1 according to a load of the gas turbine 138 in dependance upon a predetermined relationship between the supply rate of the diffusion combustion fuel F1 and the load of the gas turbine 138 as shown by a solid line in FIG. 4A, and controls a supply rate of the pre-mix combustion fuel F2 in dependance upon the load of the gas turbine 138 on the basis of a predetermined relationship between the supply rate of the pre-mix combustion fuel F2 and the load of the gas turbine 138 as shown by a broken line in FIG. 4A. Further, the controller 119 controls the open area of the pre-mix combustion air supply orifices 133 with the valve 118 being driven by the driver 121 in dependance upon the load of the gas turbine 138 on the basis of a predetermined common relationship between the open area of the pre-mix combustion air supply orifices 133 and the load of the gas turbine 138 as shown in FIG. 4B.
Japanese Patent Unexamined Publication No. 61-210233 proposes a construction in which a fuel supply rate for each of the combustion chambers is controlled in accordance with a difference between a temperature of a turbine exhaust gas from each of the combustion chambers and an average value of the turbine exhaust gas temperatures from all of the combustion chambers so that the turbine exhaust gas temperatures from all of the combustion chambers are substantially equal to each other.
Japanese Patent Unexamined Publication No. 1-150715 proposes a construction in which both of a flow rate of a main combustion air for burning a solid fuel and a flow rate of a supplemental combustion air for burning a supplemental fuel are simultaneously increased or decreased in accordance with a density e.g. concentration of a component of the turbine exhaust gas.